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Linux 4.1.16
[linux/fpc-iii.git] / net / ipv6 / ip6_fib.c
blobbde57b113009794637a07b405173bef1fd3c6fb3
1 /*
2 * Linux INET6 implementation
3 * Forwarding Information Database
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 *
13 * Changes:
14 * Yuji SEKIYA @USAGI: Support default route on router node;
15 * remove ip6_null_entry from the top of
16 * routing table.
17 * Ville Nuorvala: Fixed routing subtrees.
18 */
19
20 #define pr_fmt(fmt) "IPv6: " fmt
21
22 #include <linux/errno.h>
23 #include <linux/types.h>
24 #include <linux/net.h>
25 #include <linux/route.h>
26 #include <linux/netdevice.h>
27 #include <linux/in6.h>
28 #include <linux/init.h>
29 #include <linux/list.h>
30 #include <linux/slab.h>
31
32 #include <net/ipv6.h>
33 #include <net/ndisc.h>
34 #include <net/addrconf.h>
35
36 #include <net/ip6_fib.h>
37 #include <net/ip6_route.h>
38
39 #define RT6_DEBUG 2
40
41 #if RT6_DEBUG >= 3
42 #define RT6_TRACE(x...) pr_debug(x)
43 #else
44 #define RT6_TRACE(x...) do { ; } while (0)
45 #endif
46
47 static struct kmem_cache *fib6_node_kmem __read_mostly;
48
49 struct fib6_cleaner {
50 struct fib6_walker w;
51 struct net *net;
52 int (*func)(struct rt6_info *, void *arg);
53 int sernum;
54 void *arg;
55 };
56
57 static DEFINE_RWLOCK(fib6_walker_lock);
58
59 #ifdef CONFIG_IPV6_SUBTREES
60 #define FWS_INIT FWS_S
61 #else
62 #define FWS_INIT FWS_L
63 #endif
64
65 static void fib6_prune_clones(struct net *net, struct fib6_node *fn);
66 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn);
67 static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn);
68 static int fib6_walk(struct fib6_walker *w);
69 static int fib6_walk_continue(struct fib6_walker *w);
70
71 /*
72 * A routing update causes an increase of the serial number on the
73 * affected subtree. This allows for cached routes to be asynchronously
74 * tested when modifications are made to the destination cache as a
75 * result of redirects, path MTU changes, etc.
76 */
77
78 static void fib6_gc_timer_cb(unsigned long arg);
79
80 static LIST_HEAD(fib6_walkers);
81 #define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh)
82
83 static void fib6_walker_link(struct fib6_walker *w)
84 {
85 write_lock_bh(&fib6_walker_lock);
86 list_add(&w->lh, &fib6_walkers);
87 write_unlock_bh(&fib6_walker_lock);
88 }
89
90 static void fib6_walker_unlink(struct fib6_walker *w)
91 {
92 write_lock_bh(&fib6_walker_lock);
93 list_del(&w->lh);
94 write_unlock_bh(&fib6_walker_lock);
95 }
96
97 static int fib6_new_sernum(struct net *net)
98 {
99 int new, old;
100
101 do {
102 old = atomic_read(&net->ipv6.fib6_sernum);
103 new = old < INT_MAX ? old + 1 : 1;
104 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum,
105 old, new) != old);
106 return new;
107 }
108
109 enum {
110 FIB6_NO_SERNUM_CHANGE = 0,
111 };
112
113 /*
114 * Auxiliary address test functions for the radix tree.
115 *
116 * These assume a 32bit processor (although it will work on
117 * 64bit processors)
118 */
119
120 /*
121 * test bit
122 */
123 #if defined(__LITTLE_ENDIAN)
124 # define BITOP_BE32_SWIZZLE (0x1F & ~7)
125 #else
126 # define BITOP_BE32_SWIZZLE 0
127 #endif
128
129 static __be32 addr_bit_set(const void *token, int fn_bit)
130 {
131 const __be32 *addr = token;
132 /*
133 * Here,
134 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
135 * is optimized version of
136 * htonl(1 << ((~fn_bit)&0x1F))
137 * See include/asm-generic/bitops/le.h.
138 */
139 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) &
140 addr[fn_bit >> 5];
141 }
142
143 static struct fib6_node *node_alloc(void)
144 {
145 struct fib6_node *fn;
146
147 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
148
149 return fn;
150 }
151
152 static void node_free(struct fib6_node *fn)
153 {
154 kmem_cache_free(fib6_node_kmem, fn);
155 }
156
157 static void rt6_release(struct rt6_info *rt)
158 {
159 if (atomic_dec_and_test(&rt->rt6i_ref))
160 dst_free(&rt->dst);
161 }
162
163 static void fib6_link_table(struct net *net, struct fib6_table *tb)
164 {
165 unsigned int h;
166
167 /*
168 * Initialize table lock at a single place to give lockdep a key,
169 * tables aren't visible prior to being linked to the list.
170 */
171 rwlock_init(&tb->tb6_lock);
172
173 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
174
175 /*
176 * No protection necessary, this is the only list mutatation
177 * operation, tables never disappear once they exist.
178 */
179 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
180 }
181
182 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
183
184 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
185 {
186 struct fib6_table *table;
187
188 table = kzalloc(sizeof(*table), GFP_ATOMIC);
189 if (table) {
190 table->tb6_id = id;
191 table->tb6_root.leaf = net->ipv6.ip6_null_entry;
192 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
193 inet_peer_base_init(&table->tb6_peers);
194 }
195
196 return table;
197 }
198
199 struct fib6_table *fib6_new_table(struct net *net, u32 id)
200 {
201 struct fib6_table *tb;
202
203 if (id == 0)
204 id = RT6_TABLE_MAIN;
205 tb = fib6_get_table(net, id);
206 if (tb)
207 return tb;
208
209 tb = fib6_alloc_table(net, id);
210 if (tb)
211 fib6_link_table(net, tb);
212
213 return tb;
214 }
215
216 struct fib6_table *fib6_get_table(struct net *net, u32 id)
217 {
218 struct fib6_table *tb;
219 struct hlist_head *head;
220 unsigned int h;
221
222 if (id == 0)
223 id = RT6_TABLE_MAIN;
224 h = id & (FIB6_TABLE_HASHSZ - 1);
225 rcu_read_lock();
226 head = &net->ipv6.fib_table_hash[h];
227 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
228 if (tb->tb6_id == id) {
229 rcu_read_unlock();
230 return tb;
231 }
232 }
233 rcu_read_unlock();
234
235 return NULL;
236 }
237
238 static void __net_init fib6_tables_init(struct net *net)
239 {
240 fib6_link_table(net, net->ipv6.fib6_main_tbl);
241 fib6_link_table(net, net->ipv6.fib6_local_tbl);
242 }
243 #else
244
245 struct fib6_table *fib6_new_table(struct net *net, u32 id)
246 {
247 return fib6_get_table(net, id);
248 }
249
250 struct fib6_table *fib6_get_table(struct net *net, u32 id)
251 {
252 return net->ipv6.fib6_main_tbl;
253 }
254
255 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
256 int flags, pol_lookup_t lookup)
257 {
258 return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl6, flags);
259 }
260
261 static void __net_init fib6_tables_init(struct net *net)
262 {
263 fib6_link_table(net, net->ipv6.fib6_main_tbl);
264 }
265
266 #endif
267
268 static int fib6_dump_node(struct fib6_walker *w)
269 {
270 int res;
271 struct rt6_info *rt;
272
273 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
274 res = rt6_dump_route(rt, w->args);
275 if (res < 0) {
276 /* Frame is full, suspend walking */
277 w->leaf = rt;
278 return 1;
279 }
280 }
281 w->leaf = NULL;
282 return 0;
283 }
284
285 static void fib6_dump_end(struct netlink_callback *cb)
286 {
287 struct fib6_walker *w = (void *)cb->args[2];
288
289 if (w) {
290 if (cb->args[4]) {
291 cb->args[4] = 0;
292 fib6_walker_unlink(w);
293 }
294 cb->args[2] = 0;
295 kfree(w);
296 }
297 cb->done = (void *)cb->args[3];
298 cb->args[1] = 3;
299 }
300
301 static int fib6_dump_done(struct netlink_callback *cb)
302 {
303 fib6_dump_end(cb);
304 return cb->done ? cb->done(cb) : 0;
305 }
306
307 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
308 struct netlink_callback *cb)
309 {
310 struct fib6_walker *w;
311 int res;
312
313 w = (void *)cb->args[2];
314 w->root = &table->tb6_root;
315
316 if (cb->args[4] == 0) {
317 w->count = 0;
318 w->skip = 0;
319
320 read_lock_bh(&table->tb6_lock);
321 res = fib6_walk(w);
322 read_unlock_bh(&table->tb6_lock);
323 if (res > 0) {
324 cb->args[4] = 1;
325 cb->args[5] = w->root->fn_sernum;
326 }
327 } else {
328 if (cb->args[5] != w->root->fn_sernum) {
329 /* Begin at the root if the tree changed */
330 cb->args[5] = w->root->fn_sernum;
331 w->state = FWS_INIT;
332 w->node = w->root;
333 w->skip = w->count;
334 } else
335 w->skip = 0;
336
337 read_lock_bh(&table->tb6_lock);
338 res = fib6_walk_continue(w);
339 read_unlock_bh(&table->tb6_lock);
340 if (res <= 0) {
341 fib6_walker_unlink(w);
342 cb->args[4] = 0;
343 }
344 }
345
346 return res;
347 }
348
349 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
350 {
351 struct net *net = sock_net(skb->sk);
352 unsigned int h, s_h;
353 unsigned int e = 0, s_e;
354 struct rt6_rtnl_dump_arg arg;
355 struct fib6_walker *w;
356 struct fib6_table *tb;
357 struct hlist_head *head;
358 int res = 0;
359
360 s_h = cb->args[0];
361 s_e = cb->args[1];
362
363 w = (void *)cb->args[2];
364 if (!w) {
365 /* New dump:
366 *
367 * 1. hook callback destructor.
368 */
369 cb->args[3] = (long)cb->done;
370 cb->done = fib6_dump_done;
371
372 /*
373 * 2. allocate and initialize walker.
374 */
375 w = kzalloc(sizeof(*w), GFP_ATOMIC);
376 if (!w)
377 return -ENOMEM;
378 w->func = fib6_dump_node;
379 cb->args[2] = (long)w;
380 }
381
382 arg.skb = skb;
383 arg.cb = cb;
384 arg.net = net;
385 w->args = &arg;
386
387 rcu_read_lock();
388 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
389 e = 0;
390 head = &net->ipv6.fib_table_hash[h];
391 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
392 if (e < s_e)
393 goto next;
394 res = fib6_dump_table(tb, skb, cb);
395 if (res != 0)
396 goto out;
397 next:
398 e++;
399 }
400 }
401 out:
402 rcu_read_unlock();
403 cb->args[1] = e;
404 cb->args[0] = h;
405
406 res = res < 0 ? res : skb->len;
407 if (res <= 0)
408 fib6_dump_end(cb);
409 return res;
410 }
411
412 /*
413 * Routing Table
414 *
415 * return the appropriate node for a routing tree "add" operation
416 * by either creating and inserting or by returning an existing
417 * node.
418 */
419
420 static struct fib6_node *fib6_add_1(struct fib6_node *root,
421 struct in6_addr *addr, int plen,
422 int offset, int allow_create,
423 int replace_required, int sernum)
424 {
425 struct fib6_node *fn, *in, *ln;
426 struct fib6_node *pn = NULL;
427 struct rt6key *key;
428 int bit;
429 __be32 dir = 0;
430
431 RT6_TRACE("fib6_add_1\n");
432
433 /* insert node in tree */
434
435 fn = root;
436
437 do {
438 key = (struct rt6key *)((u8 *)fn->leaf + offset);
439
440 /*
441 * Prefix match
442 */
443 if (plen < fn->fn_bit ||
444 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
445 if (!allow_create) {
446 if (replace_required) {
447 pr_warn("Can't replace route, no match found\n");
448 return ERR_PTR(-ENOENT);
449 }
450 pr_warn("NLM_F_CREATE should be set when creating new route\n");
451 }
452 goto insert_above;
453 }
454
455 /*
456 * Exact match ?
457 */
458
459 if (plen == fn->fn_bit) {
460 /* clean up an intermediate node */
461 if (!(fn->fn_flags & RTN_RTINFO)) {
462 rt6_release(fn->leaf);
463 fn->leaf = NULL;
464 }
465
466 fn->fn_sernum = sernum;
467
468 return fn;
469 }
470
471 /*
472 * We have more bits to go
473 */
474
475 /* Try to walk down on tree. */
476 fn->fn_sernum = sernum;
477 dir = addr_bit_set(addr, fn->fn_bit);
478 pn = fn;
479 fn = dir ? fn->right : fn->left;
480 } while (fn);
481
482 if (!allow_create) {
483 /* We should not create new node because
484 * NLM_F_REPLACE was specified without NLM_F_CREATE
485 * I assume it is safe to require NLM_F_CREATE when
486 * REPLACE flag is used! Later we may want to remove the
487 * check for replace_required, because according
488 * to netlink specification, NLM_F_CREATE
489 * MUST be specified if new route is created.
490 * That would keep IPv6 consistent with IPv4
491 */
492 if (replace_required) {
493 pr_warn("Can't replace route, no match found\n");
494 return ERR_PTR(-ENOENT);
495 }
496 pr_warn("NLM_F_CREATE should be set when creating new route\n");
497 }
498 /*
499 * We walked to the bottom of tree.
500 * Create new leaf node without children.
501 */
502
503 ln = node_alloc();
504
505 if (!ln)
506 return ERR_PTR(-ENOMEM);
507 ln->fn_bit = plen;
508
509 ln->parent = pn;
510 ln->fn_sernum = sernum;
511
512 if (dir)
513 pn->right = ln;
514 else
515 pn->left = ln;
516
517 return ln;
518
519
520 insert_above:
521 /*
522 * split since we don't have a common prefix anymore or
523 * we have a less significant route.
524 * we've to insert an intermediate node on the list
525 * this new node will point to the one we need to create
526 * and the current
527 */
528
529 pn = fn->parent;
530
531 /* find 1st bit in difference between the 2 addrs.
532
533 See comment in __ipv6_addr_diff: bit may be an invalid value,
534 but if it is >= plen, the value is ignored in any case.
535 */
536
537 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr));
538
539 /*
540 * (intermediate)[in]
541 * / \
542 * (new leaf node)[ln] (old node)[fn]
543 */
544 if (plen > bit) {
545 in = node_alloc();
546 ln = node_alloc();
547
548 if (!in || !ln) {
549 if (in)
550 node_free(in);
551 if (ln)
552 node_free(ln);
553 return ERR_PTR(-ENOMEM);
554 }
555
556 /*
557 * new intermediate node.
558 * RTN_RTINFO will
559 * be off since that an address that chooses one of
560 * the branches would not match less specific routes
561 * in the other branch
562 */
563
564 in->fn_bit = bit;
565
566 in->parent = pn;
567 in->leaf = fn->leaf;
568 atomic_inc(&in->leaf->rt6i_ref);
569
570 in->fn_sernum = sernum;
571
572 /* update parent pointer */
573 if (dir)
574 pn->right = in;
575 else
576 pn->left = in;
577
578 ln->fn_bit = plen;
579
580 ln->parent = in;
581 fn->parent = in;
582
583 ln->fn_sernum = sernum;
584
585 if (addr_bit_set(addr, bit)) {
586 in->right = ln;
587 in->left = fn;
588 } else {
589 in->left = ln;
590 in->right = fn;
591 }
592 } else { /* plen <= bit */
593
594 /*
595 * (new leaf node)[ln]
596 * / \
597 * (old node)[fn] NULL
598 */
599
600 ln = node_alloc();
601
602 if (!ln)
603 return ERR_PTR(-ENOMEM);
604
605 ln->fn_bit = plen;
606
607 ln->parent = pn;
608
609 ln->fn_sernum = sernum;
610
611 if (dir)
612 pn->right = ln;
613 else
614 pn->left = ln;
615
616 if (addr_bit_set(&key->addr, plen))
617 ln->right = fn;
618 else
619 ln->left = fn;
620
621 fn->parent = ln;
622 }
623 return ln;
624 }
625
626 static bool rt6_qualify_for_ecmp(struct rt6_info *rt)
627 {
628 return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) ==
629 RTF_GATEWAY;
630 }
631
632 static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc)
633 {
634 int i;
635
636 for (i = 0; i < RTAX_MAX; i++) {
637 if (test_bit(i, mxc->mx_valid))
638 mp[i] = mxc->mx[i];
639 }
640 }
641
642 static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc)
643 {
644 if (!mxc->mx)
645 return 0;
646
647 if (dst->flags & DST_HOST) {
648 u32 *mp = dst_metrics_write_ptr(dst);
649
650 if (unlikely(!mp))
651 return -ENOMEM;
652
653 fib6_copy_metrics(mp, mxc);
654 } else {
655 dst_init_metrics(dst, mxc->mx, false);
656
657 /* We've stolen mx now. */
658 mxc->mx = NULL;
659 }
660
661 return 0;
662 }
663
664 static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn,
665 struct net *net)
666 {
667 if (atomic_read(&rt->rt6i_ref) != 1) {
668 /* This route is used as dummy address holder in some split
669 * nodes. It is not leaked, but it still holds other resources,
670 * which must be released in time. So, scan ascendant nodes
671 * and replace dummy references to this route with references
672 * to still alive ones.
673 */
674 while (fn) {
675 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) {
676 fn->leaf = fib6_find_prefix(net, fn);
677 atomic_inc(&fn->leaf->rt6i_ref);
678 rt6_release(rt);
679 }
680 fn = fn->parent;
681 }
682 /* No more references are possible at this point. */
683 BUG_ON(atomic_read(&rt->rt6i_ref) != 1);
684 }
685 }
686
687 /*
688 * Insert routing information in a node.
689 */
690
691 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
692 struct nl_info *info, struct mx6_config *mxc)
693 {
694 struct rt6_info *iter = NULL;
695 struct rt6_info **ins;
696 struct rt6_info **fallback_ins = NULL;
697 int replace = (info->nlh &&
698 (info->nlh->nlmsg_flags & NLM_F_REPLACE));
699 int add = (!info->nlh ||
700 (info->nlh->nlmsg_flags & NLM_F_CREATE));
701 int found = 0;
702 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
703 int err;
704
705 ins = &fn->leaf;
706
707 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) {
708 /*
709 * Search for duplicates
710 */
711
712 if (iter->rt6i_metric == rt->rt6i_metric) {
713 /*
714 * Same priority level
715 */
716 if (info->nlh &&
717 (info->nlh->nlmsg_flags & NLM_F_EXCL))
718 return -EEXIST;
719 if (replace) {
720 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) {
721 found++;
722 break;
723 }
724 if (rt_can_ecmp)
725 fallback_ins = fallback_ins ?: ins;
726 goto next_iter;
727 }
728
729 if (iter->dst.dev == rt->dst.dev &&
730 iter->rt6i_idev == rt->rt6i_idev &&
731 ipv6_addr_equal(&iter->rt6i_gateway,
732 &rt->rt6i_gateway)) {
733 if (rt->rt6i_nsiblings)
734 rt->rt6i_nsiblings = 0;
735 if (!(iter->rt6i_flags & RTF_EXPIRES))
736 return -EEXIST;
737 if (!(rt->rt6i_flags & RTF_EXPIRES))
738 rt6_clean_expires(iter);
739 else
740 rt6_set_expires(iter, rt->dst.expires);
741 return -EEXIST;
742 }
743 /* If we have the same destination and the same metric,
744 * but not the same gateway, then the route we try to
745 * add is sibling to this route, increment our counter
746 * of siblings, and later we will add our route to the
747 * list.
748 * Only static routes (which don't have flag
749 * RTF_EXPIRES) are used for ECMPv6.
750 *
751 * To avoid long list, we only had siblings if the
752 * route have a gateway.
753 */
754 if (rt_can_ecmp &&
755 rt6_qualify_for_ecmp(iter))
756 rt->rt6i_nsiblings++;
757 }
758
759 if (iter->rt6i_metric > rt->rt6i_metric)
760 break;
761
762 next_iter:
763 ins = &iter->dst.rt6_next;
764 }
765
766 if (fallback_ins && !found) {
767 /* No ECMP-able route found, replace first non-ECMP one */
768 ins = fallback_ins;
769 iter = *ins;
770 found++;
771 }
772
773 /* Reset round-robin state, if necessary */
774 if (ins == &fn->leaf)
775 fn->rr_ptr = NULL;
776
777 /* Link this route to others same route. */
778 if (rt->rt6i_nsiblings) {
779 unsigned int rt6i_nsiblings;
780 struct rt6_info *sibling, *temp_sibling;
781
782 /* Find the first route that have the same metric */
783 sibling = fn->leaf;
784 while (sibling) {
785 if (sibling->rt6i_metric == rt->rt6i_metric &&
786 rt6_qualify_for_ecmp(sibling)) {
787 list_add_tail(&rt->rt6i_siblings,
788 &sibling->rt6i_siblings);
789 break;
790 }
791 sibling = sibling->dst.rt6_next;
792 }
793 /* For each sibling in the list, increment the counter of
794 * siblings. BUG() if counters does not match, list of siblings
795 * is broken!
796 */
797 rt6i_nsiblings = 0;
798 list_for_each_entry_safe(sibling, temp_sibling,
799 &rt->rt6i_siblings, rt6i_siblings) {
800 sibling->rt6i_nsiblings++;
801 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings);
802 rt6i_nsiblings++;
803 }
804 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings);
805 }
806
807 /*
808 * insert node
809 */
810 if (!replace) {
811 if (!add)
812 pr_warn("NLM_F_CREATE should be set when creating new route\n");
813
814 add:
815 err = fib6_commit_metrics(&rt->dst, mxc);
816 if (err)
817 return err;
818
819 rt->dst.rt6_next = iter;
820 *ins = rt;
821 rt->rt6i_node = fn;
822 atomic_inc(&rt->rt6i_ref);
823 inet6_rt_notify(RTM_NEWROUTE, rt, info);
824 info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
825
826 if (!(fn->fn_flags & RTN_RTINFO)) {
827 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
828 fn->fn_flags |= RTN_RTINFO;
829 }
830
831 } else {
832 int nsiblings;
833
834 if (!found) {
835 if (add)
836 goto add;
837 pr_warn("NLM_F_REPLACE set, but no existing node found!\n");
838 return -ENOENT;
839 }
840
841 err = fib6_commit_metrics(&rt->dst, mxc);
842 if (err)
843 return err;
844
845 *ins = rt;
846 rt->rt6i_node = fn;
847 rt->dst.rt6_next = iter->dst.rt6_next;
848 atomic_inc(&rt->rt6i_ref);
849 inet6_rt_notify(RTM_NEWROUTE, rt, info);
850 if (!(fn->fn_flags & RTN_RTINFO)) {
851 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
852 fn->fn_flags |= RTN_RTINFO;
853 }
854 nsiblings = iter->rt6i_nsiblings;
855 fib6_purge_rt(iter, fn, info->nl_net);
856 rt6_release(iter);
857
858 if (nsiblings) {
859 /* Replacing an ECMP route, remove all siblings */
860 ins = &rt->dst.rt6_next;
861 iter = *ins;
862 while (iter) {
863 if (rt6_qualify_for_ecmp(iter)) {
864 *ins = iter->dst.rt6_next;
865 fib6_purge_rt(iter, fn, info->nl_net);
866 rt6_release(iter);
867 nsiblings--;
868 } else {
869 ins = &iter->dst.rt6_next;
870 }
871 iter = *ins;
872 }
873 WARN_ON(nsiblings != 0);
874 }
875 }
876
877 return 0;
878 }
879
880 static void fib6_start_gc(struct net *net, struct rt6_info *rt)
881 {
882 if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
883 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE)))
884 mod_timer(&net->ipv6.ip6_fib_timer,
885 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
886 }
887
888 void fib6_force_start_gc(struct net *net)
889 {
890 if (!timer_pending(&net->ipv6.ip6_fib_timer))
891 mod_timer(&net->ipv6.ip6_fib_timer,
892 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
893 }
894
895 /*
896 * Add routing information to the routing tree.
897 * <destination addr>/<source addr>
898 * with source addr info in sub-trees
899 */
900
901 int fib6_add(struct fib6_node *root, struct rt6_info *rt,
902 struct nl_info *info, struct mx6_config *mxc)
903 {
904 struct fib6_node *fn, *pn = NULL;
905 int err = -ENOMEM;
906 int allow_create = 1;
907 int replace_required = 0;
908 int sernum = fib6_new_sernum(info->nl_net);
909
910 if (info->nlh) {
911 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
912 allow_create = 0;
913 if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
914 replace_required = 1;
915 }
916 if (!allow_create && !replace_required)
917 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
918
919 fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
920 offsetof(struct rt6_info, rt6i_dst), allow_create,
921 replace_required, sernum);
922 if (IS_ERR(fn)) {
923 err = PTR_ERR(fn);
924 fn = NULL;
925 goto out;
926 }
927
928 pn = fn;
929
930 #ifdef CONFIG_IPV6_SUBTREES
931 if (rt->rt6i_src.plen) {
932 struct fib6_node *sn;
933
934 if (!fn->subtree) {
935 struct fib6_node *sfn;
936
937 /*
938 * Create subtree.
939 *
940 * fn[main tree]
941 * |
942 * sfn[subtree root]
943 * \
944 * sn[new leaf node]
945 */
946
947 /* Create subtree root node */
948 sfn = node_alloc();
949 if (!sfn)
950 goto st_failure;
951
952 sfn->leaf = info->nl_net->ipv6.ip6_null_entry;
953 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
954 sfn->fn_flags = RTN_ROOT;
955 sfn->fn_sernum = sernum;
956
957 /* Now add the first leaf node to new subtree */
958
959 sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
960 rt->rt6i_src.plen,
961 offsetof(struct rt6_info, rt6i_src),
962 allow_create, replace_required, sernum);
963
964 if (IS_ERR(sn)) {
965 /* If it is failed, discard just allocated
966 root, and then (in st_failure) stale node
967 in main tree.
968 */
969 node_free(sfn);
970 err = PTR_ERR(sn);
971 goto st_failure;
972 }
973
974 /* Now link new subtree to main tree */
975 sfn->parent = fn;
976 fn->subtree = sfn;
977 } else {
978 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
979 rt->rt6i_src.plen,
980 offsetof(struct rt6_info, rt6i_src),
981 allow_create, replace_required, sernum);
982
983 if (IS_ERR(sn)) {
984 err = PTR_ERR(sn);
985 goto st_failure;
986 }
987 }
988
989 if (!fn->leaf) {
990 fn->leaf = rt;
991 atomic_inc(&rt->rt6i_ref);
992 }
993 fn = sn;
994 }
995 #endif
996
997 err = fib6_add_rt2node(fn, rt, info, mxc);
998 if (!err) {
999 fib6_start_gc(info->nl_net, rt);
1000 if (!(rt->rt6i_flags & RTF_CACHE))
1001 fib6_prune_clones(info->nl_net, pn);
1002 }
1003
1004 out:
1005 if (err) {
1006 #ifdef CONFIG_IPV6_SUBTREES
1007 /*
1008 * If fib6_add_1 has cleared the old leaf pointer in the
1009 * super-tree leaf node we have to find a new one for it.
1010 */
1011 if (pn != fn && pn->leaf == rt) {
1012 pn->leaf = NULL;
1013 atomic_dec(&rt->rt6i_ref);
1014 }
1015 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
1016 pn->leaf = fib6_find_prefix(info->nl_net, pn);
1017 #if RT6_DEBUG >= 2
1018 if (!pn->leaf) {
1019 WARN_ON(pn->leaf == NULL);
1020 pn->leaf = info->nl_net->ipv6.ip6_null_entry;
1021 }
1022 #endif
1023 atomic_inc(&pn->leaf->rt6i_ref);
1024 }
1025 #endif
1026 dst_free(&rt->dst);
1027 }
1028 return err;
1029
1030 #ifdef CONFIG_IPV6_SUBTREES
1031 /* Subtree creation failed, probably main tree node
1032 is orphan. If it is, shoot it.
1033 */
1034 st_failure:
1035 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
1036 fib6_repair_tree(info->nl_net, fn);
1037 dst_free(&rt->dst);
1038 return err;
1039 #endif
1040 }
1041
1042 /*
1043 * Routing tree lookup
1044 *
1045 */
1046
1047 struct lookup_args {
1048 int offset; /* key offset on rt6_info */
1049 const struct in6_addr *addr; /* search key */
1050 };
1051
1052 static struct fib6_node *fib6_lookup_1(struct fib6_node *root,
1053 struct lookup_args *args)
1054 {
1055 struct fib6_node *fn;
1056 __be32 dir;
1057
1058 if (unlikely(args->offset == 0))
1059 return NULL;
1060
1061 /*
1062 * Descend on a tree
1063 */
1064
1065 fn = root;
1066
1067 for (;;) {
1068 struct fib6_node *next;
1069
1070 dir = addr_bit_set(args->addr, fn->fn_bit);
1071
1072 next = dir ? fn->right : fn->left;
1073
1074 if (next) {
1075 fn = next;
1076 continue;
1077 }
1078 break;
1079 }
1080
1081 while (fn) {
1082 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
1083 struct rt6key *key;
1084
1085 key = (struct rt6key *) ((u8 *) fn->leaf +
1086 args->offset);
1087
1088 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
1089 #ifdef CONFIG_IPV6_SUBTREES
1090 if (fn->subtree) {
1091 struct fib6_node *sfn;
1092 sfn = fib6_lookup_1(fn->subtree,
1093 args + 1);
1094 if (!sfn)
1095 goto backtrack;
1096 fn = sfn;
1097 }
1098 #endif
1099 if (fn->fn_flags & RTN_RTINFO)
1100 return fn;
1101 }
1102 }
1103 #ifdef CONFIG_IPV6_SUBTREES
1104 backtrack:
1105 #endif
1106 if (fn->fn_flags & RTN_ROOT)
1107 break;
1108
1109 fn = fn->parent;
1110 }
1111
1112 return NULL;
1113 }
1114
1115 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr,
1116 const struct in6_addr *saddr)
1117 {
1118 struct fib6_node *fn;
1119 struct lookup_args args[] = {
1120 {
1121 .offset = offsetof(struct rt6_info, rt6i_dst),
1122 .addr = daddr,
1123 },
1124 #ifdef CONFIG_IPV6_SUBTREES
1125 {
1126 .offset = offsetof(struct rt6_info, rt6i_src),
1127 .addr = saddr,
1128 },
1129 #endif
1130 {
1131 .offset = 0, /* sentinel */
1132 }
1133 };
1134
1135 fn = fib6_lookup_1(root, daddr ? args : args + 1);
1136 if (!fn || fn->fn_flags & RTN_TL_ROOT)
1137 fn = root;
1138
1139 return fn;
1140 }
1141
1142 /*
1143 * Get node with specified destination prefix (and source prefix,
1144 * if subtrees are used)
1145 */
1146
1147
1148 static struct fib6_node *fib6_locate_1(struct fib6_node *root,
1149 const struct in6_addr *addr,
1150 int plen, int offset)
1151 {
1152 struct fib6_node *fn;
1153
1154 for (fn = root; fn ; ) {
1155 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
1156
1157 /*
1158 * Prefix match
1159 */
1160 if (plen < fn->fn_bit ||
1161 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
1162 return NULL;
1163
1164 if (plen == fn->fn_bit)
1165 return fn;
1166
1167 /*
1168 * We have more bits to go
1169 */
1170 if (addr_bit_set(addr, fn->fn_bit))
1171 fn = fn->right;
1172 else
1173 fn = fn->left;
1174 }
1175 return NULL;
1176 }
1177
1178 struct fib6_node *fib6_locate(struct fib6_node *root,
1179 const struct in6_addr *daddr, int dst_len,
1180 const struct in6_addr *saddr, int src_len)
1181 {
1182 struct fib6_node *fn;
1183
1184 fn = fib6_locate_1(root, daddr, dst_len,
1185 offsetof(struct rt6_info, rt6i_dst));
1186
1187 #ifdef CONFIG_IPV6_SUBTREES
1188 if (src_len) {
1189 WARN_ON(saddr == NULL);
1190 if (fn && fn->subtree)
1191 fn = fib6_locate_1(fn->subtree, saddr, src_len,
1192 offsetof(struct rt6_info, rt6i_src));
1193 }
1194 #endif
1195
1196 if (fn && fn->fn_flags & RTN_RTINFO)
1197 return fn;
1198
1199 return NULL;
1200 }
1201
1202
1203 /*
1204 * Deletion
1205 *
1206 */
1207
1208 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
1209 {
1210 if (fn->fn_flags & RTN_ROOT)
1211 return net->ipv6.ip6_null_entry;
1212
1213 while (fn) {
1214 if (fn->left)
1215 return fn->left->leaf;
1216 if (fn->right)
1217 return fn->right->leaf;
1218
1219 fn = FIB6_SUBTREE(fn);
1220 }
1221 return NULL;
1222 }
1223
1224 /*
1225 * Called to trim the tree of intermediate nodes when possible. "fn"
1226 * is the node we want to try and remove.
1227 */
1228
1229 static struct fib6_node *fib6_repair_tree(struct net *net,
1230 struct fib6_node *fn)
1231 {
1232 int children;
1233 int nstate;
1234 struct fib6_node *child, *pn;
1235 struct fib6_walker *w;
1236 int iter = 0;
1237
1238 for (;;) {
1239 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1240 iter++;
1241
1242 WARN_ON(fn->fn_flags & RTN_RTINFO);
1243 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1244 WARN_ON(fn->leaf);
1245
1246 children = 0;
1247 child = NULL;
1248 if (fn->right)
1249 child = fn->right, children |= 1;
1250 if (fn->left)
1251 child = fn->left, children |= 2;
1252
1253 if (children == 3 || FIB6_SUBTREE(fn)
1254 #ifdef CONFIG_IPV6_SUBTREES
1255 /* Subtree root (i.e. fn) may have one child */
1256 || (children && fn->fn_flags & RTN_ROOT)
1257 #endif
1258 ) {
1259 fn->leaf = fib6_find_prefix(net, fn);
1260 #if RT6_DEBUG >= 2
1261 if (!fn->leaf) {
1262 WARN_ON(!fn->leaf);
1263 fn->leaf = net->ipv6.ip6_null_entry;
1264 }
1265 #endif
1266 atomic_inc(&fn->leaf->rt6i_ref);
1267 return fn->parent;
1268 }
1269
1270 pn = fn->parent;
1271 #ifdef CONFIG_IPV6_SUBTREES
1272 if (FIB6_SUBTREE(pn) == fn) {
1273 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1274 FIB6_SUBTREE(pn) = NULL;
1275 nstate = FWS_L;
1276 } else {
1277 WARN_ON(fn->fn_flags & RTN_ROOT);
1278 #endif
1279 if (pn->right == fn)
1280 pn->right = child;
1281 else if (pn->left == fn)
1282 pn->left = child;
1283 #if RT6_DEBUG >= 2
1284 else
1285 WARN_ON(1);
1286 #endif
1287 if (child)
1288 child->parent = pn;
1289 nstate = FWS_R;
1290 #ifdef CONFIG_IPV6_SUBTREES
1291 }
1292 #endif
1293
1294 read_lock(&fib6_walker_lock);
1295 FOR_WALKERS(w) {
1296 if (!child) {
1297 if (w->root == fn) {
1298 w->root = w->node = NULL;
1299 RT6_TRACE("W %p adjusted by delroot 1\n", w);
1300 } else if (w->node == fn) {
1301 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1302 w->node = pn;
1303 w->state = nstate;
1304 }
1305 } else {
1306 if (w->root == fn) {
1307 w->root = child;
1308 RT6_TRACE("W %p adjusted by delroot 2\n", w);
1309 }
1310 if (w->node == fn) {
1311 w->node = child;
1312 if (children&2) {
1313 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1314 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT;
1315 } else {
1316 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1317 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT;
1318 }
1319 }
1320 }
1321 }
1322 read_unlock(&fib6_walker_lock);
1323
1324 node_free(fn);
1325 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
1326 return pn;
1327
1328 rt6_release(pn->leaf);
1329 pn->leaf = NULL;
1330 fn = pn;
1331 }
1332 }
1333
1334 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
1335 struct nl_info *info)
1336 {
1337 struct fib6_walker *w;
1338 struct rt6_info *rt = *rtp;
1339 struct net *net = info->nl_net;
1340
1341 RT6_TRACE("fib6_del_route\n");
1342
1343 /* Unlink it */
1344 *rtp = rt->dst.rt6_next;
1345 rt->rt6i_node = NULL;
1346 net->ipv6.rt6_stats->fib_rt_entries--;
1347 net->ipv6.rt6_stats->fib_discarded_routes++;
1348
1349 /* Reset round-robin state, if necessary */
1350 if (fn->rr_ptr == rt)
1351 fn->rr_ptr = NULL;
1352
1353 /* Remove this entry from other siblings */
1354 if (rt->rt6i_nsiblings) {
1355 struct rt6_info *sibling, *next_sibling;
1356
1357 list_for_each_entry_safe(sibling, next_sibling,
1358 &rt->rt6i_siblings, rt6i_siblings)
1359 sibling->rt6i_nsiblings--;
1360 rt->rt6i_nsiblings = 0;
1361 list_del_init(&rt->rt6i_siblings);
1362 }
1363
1364 /* Adjust walkers */
1365 read_lock(&fib6_walker_lock);
1366 FOR_WALKERS(w) {
1367 if (w->state == FWS_C && w->leaf == rt) {
1368 RT6_TRACE("walker %p adjusted by delroute\n", w);
1369 w->leaf = rt->dst.rt6_next;
1370 if (!w->leaf)
1371 w->state = FWS_U;
1372 }
1373 }
1374 read_unlock(&fib6_walker_lock);
1375
1376 rt->dst.rt6_next = NULL;
1377
1378 /* If it was last route, expunge its radix tree node */
1379 if (!fn->leaf) {
1380 fn->fn_flags &= ~RTN_RTINFO;
1381 net->ipv6.rt6_stats->fib_route_nodes--;
1382 fn = fib6_repair_tree(net, fn);
1383 }
1384
1385 fib6_purge_rt(rt, fn, net);
1386
1387 inet6_rt_notify(RTM_DELROUTE, rt, info);
1388 rt6_release(rt);
1389 }
1390
1391 int fib6_del(struct rt6_info *rt, struct nl_info *info)
1392 {
1393 struct net *net = info->nl_net;
1394 struct fib6_node *fn = rt->rt6i_node;
1395 struct rt6_info **rtp;
1396
1397 #if RT6_DEBUG >= 2
1398 if (rt->dst.obsolete > 0) {
1399 WARN_ON(fn);
1400 return -ENOENT;
1401 }
1402 #endif
1403 if (!fn || rt == net->ipv6.ip6_null_entry)
1404 return -ENOENT;
1405
1406 WARN_ON(!(fn->fn_flags & RTN_RTINFO));
1407
1408 if (!(rt->rt6i_flags & RTF_CACHE)) {
1409 struct fib6_node *pn = fn;
1410 #ifdef CONFIG_IPV6_SUBTREES
1411 /* clones of this route might be in another subtree */
1412 if (rt->rt6i_src.plen) {
1413 while (!(pn->fn_flags & RTN_ROOT))
1414 pn = pn->parent;
1415 pn = pn->parent;
1416 }
1417 #endif
1418 fib6_prune_clones(info->nl_net, pn);
1419 }
1420
1421 /*
1422 * Walk the leaf entries looking for ourself
1423 */
1424
1425 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) {
1426 if (*rtp == rt) {
1427 fib6_del_route(fn, rtp, info);
1428 return 0;
1429 }
1430 }
1431 return -ENOENT;
1432 }
1433
1434 /*
1435 * Tree traversal function.
1436 *
1437 * Certainly, it is not interrupt safe.
1438 * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1439 * It means, that we can modify tree during walking
1440 * and use this function for garbage collection, clone pruning,
1441 * cleaning tree when a device goes down etc. etc.
1442 *
1443 * It guarantees that every node will be traversed,
1444 * and that it will be traversed only once.
1445 *
1446 * Callback function w->func may return:
1447 * 0 -> continue walking.
1448 * positive value -> walking is suspended (used by tree dumps,
1449 * and probably by gc, if it will be split to several slices)
1450 * negative value -> terminate walking.
1451 *
1452 * The function itself returns:
1453 * 0 -> walk is complete.
1454 * >0 -> walk is incomplete (i.e. suspended)
1455 * <0 -> walk is terminated by an error.
1456 */
1457
1458 static int fib6_walk_continue(struct fib6_walker *w)
1459 {
1460 struct fib6_node *fn, *pn;
1461
1462 for (;;) {
1463 fn = w->node;
1464 if (!fn)
1465 return 0;
1466
1467 if (w->prune && fn != w->root &&
1468 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) {
1469 w->state = FWS_C;
1470 w->leaf = fn->leaf;
1471 }
1472 switch (w->state) {
1473 #ifdef CONFIG_IPV6_SUBTREES
1474 case FWS_S:
1475 if (FIB6_SUBTREE(fn)) {
1476 w->node = FIB6_SUBTREE(fn);
1477 continue;
1478 }
1479 w->state = FWS_L;
1480 #endif
1481 case FWS_L:
1482 if (fn->left) {
1483 w->node = fn->left;
1484 w->state = FWS_INIT;
1485 continue;
1486 }
1487 w->state = FWS_R;
1488 case FWS_R:
1489 if (fn->right) {
1490 w->node = fn->right;
1491 w->state = FWS_INIT;
1492 continue;
1493 }
1494 w->state = FWS_C;
1495 w->leaf = fn->leaf;
1496 case FWS_C:
1497 if (w->leaf && fn->fn_flags & RTN_RTINFO) {
1498 int err;
1499
1500 if (w->skip) {
1501 w->skip--;
1502 goto skip;
1503 }
1504
1505 err = w->func(w);
1506 if (err)
1507 return err;
1508
1509 w->count++;
1510 continue;
1511 }
1512 skip:
1513 w->state = FWS_U;
1514 case FWS_U:
1515 if (fn == w->root)
1516 return 0;
1517 pn = fn->parent;
1518 w->node = pn;
1519 #ifdef CONFIG_IPV6_SUBTREES
1520 if (FIB6_SUBTREE(pn) == fn) {
1521 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1522 w->state = FWS_L;
1523 continue;
1524 }
1525 #endif
1526 if (pn->left == fn) {
1527 w->state = FWS_R;
1528 continue;
1529 }
1530 if (pn->right == fn) {
1531 w->state = FWS_C;
1532 w->leaf = w->node->leaf;
1533 continue;
1534 }
1535 #if RT6_DEBUG >= 2
1536 WARN_ON(1);
1537 #endif
1538 }
1539 }
1540 }
1541
1542 static int fib6_walk(struct fib6_walker *w)
1543 {
1544 int res;
1545
1546 w->state = FWS_INIT;
1547 w->node = w->root;
1548
1549 fib6_walker_link(w);
1550 res = fib6_walk_continue(w);
1551 if (res <= 0)
1552 fib6_walker_unlink(w);
1553 return res;
1554 }
1555
1556 static int fib6_clean_node(struct fib6_walker *w)
1557 {
1558 int res;
1559 struct rt6_info *rt;
1560 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w);
1561 struct nl_info info = {
1562 .nl_net = c->net,
1563 };
1564
1565 if (c->sernum != FIB6_NO_SERNUM_CHANGE &&
1566 w->node->fn_sernum != c->sernum)
1567 w->node->fn_sernum = c->sernum;
1568
1569 if (!c->func) {
1570 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE);
1571 w->leaf = NULL;
1572 return 0;
1573 }
1574
1575 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
1576 res = c->func(rt, c->arg);
1577 if (res < 0) {
1578 w->leaf = rt;
1579 res = fib6_del(rt, &info);
1580 if (res) {
1581 #if RT6_DEBUG >= 2
1582 pr_debug("%s: del failed: rt=%p@%p err=%d\n",
1583 __func__, rt, rt->rt6i_node, res);
1584 #endif
1585 continue;
1586 }
1587 return 0;
1588 }
1589 WARN_ON(res != 0);
1590 }
1591 w->leaf = rt;
1592 return 0;
1593 }
1594
1595 /*
1596 * Convenient frontend to tree walker.
1597 *
1598 * func is called on each route.
1599 * It may return -1 -> delete this route.
1600 * 0 -> continue walking
1601 *
1602 * prune==1 -> only immediate children of node (certainly,
1603 * ignoring pure split nodes) will be scanned.
1604 */
1605
1606 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
1607 int (*func)(struct rt6_info *, void *arg),
1608 bool prune, int sernum, void *arg)
1609 {
1610 struct fib6_cleaner c;
1611
1612 c.w.root = root;
1613 c.w.func = fib6_clean_node;
1614 c.w.prune = prune;
1615 c.w.count = 0;
1616 c.w.skip = 0;
1617 c.func = func;
1618 c.sernum = sernum;
1619 c.arg = arg;
1620 c.net = net;
1621
1622 fib6_walk(&c.w);
1623 }
1624
1625 static void __fib6_clean_all(struct net *net,
1626 int (*func)(struct rt6_info *, void *),
1627 int sernum, void *arg)
1628 {
1629 struct fib6_table *table;
1630 struct hlist_head *head;
1631 unsigned int h;
1632
1633 rcu_read_lock();
1634 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
1635 head = &net->ipv6.fib_table_hash[h];
1636 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
1637 write_lock_bh(&table->tb6_lock);
1638 fib6_clean_tree(net, &table->tb6_root,
1639 func, false, sernum, arg);
1640 write_unlock_bh(&table->tb6_lock);
1641 }
1642 }
1643 rcu_read_unlock();
1644 }
1645
1646 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *),
1647 void *arg)
1648 {
1649 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg);
1650 }
1651
1652 static int fib6_prune_clone(struct rt6_info *rt, void *arg)
1653 {
1654 if (rt->rt6i_flags & RTF_CACHE) {
1655 RT6_TRACE("pruning clone %p\n", rt);
1656 return -1;
1657 }
1658
1659 return 0;
1660 }
1661
1662 static void fib6_prune_clones(struct net *net, struct fib6_node *fn)
1663 {
1664 fib6_clean_tree(net, fn, fib6_prune_clone, true,
1665 FIB6_NO_SERNUM_CHANGE, NULL);
1666 }
1667
1668 static void fib6_flush_trees(struct net *net)
1669 {
1670 int new_sernum = fib6_new_sernum(net);
1671
1672 __fib6_clean_all(net, NULL, new_sernum, NULL);
1673 }
1674
1675 /*
1676 * Garbage collection
1677 */
1678
1679 static struct fib6_gc_args
1680 {
1681 int timeout;
1682 int more;
1683 } gc_args;
1684
1685 static int fib6_age(struct rt6_info *rt, void *arg)
1686 {
1687 unsigned long now = jiffies;
1688
1689 /*
1690 * check addrconf expiration here.
1691 * Routes are expired even if they are in use.
1692 *
1693 * Also age clones. Note, that clones are aged out
1694 * only if they are not in use now.
1695 */
1696
1697 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) {
1698 if (time_after(now, rt->dst.expires)) {
1699 RT6_TRACE("expiring %p\n", rt);
1700 return -1;
1701 }
1702 gc_args.more++;
1703 } else if (rt->rt6i_flags & RTF_CACHE) {
1704 if (atomic_read(&rt->dst.__refcnt) == 0 &&
1705 time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) {
1706 RT6_TRACE("aging clone %p\n", rt);
1707 return -1;
1708 } else if (rt->rt6i_flags & RTF_GATEWAY) {
1709 struct neighbour *neigh;
1710 __u8 neigh_flags = 0;
1711
1712 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway);
1713 if (neigh) {
1714 neigh_flags = neigh->flags;
1715 neigh_release(neigh);
1716 }
1717 if (!(neigh_flags & NTF_ROUTER)) {
1718 RT6_TRACE("purging route %p via non-router but gateway\n",
1719 rt);
1720 return -1;
1721 }
1722 }
1723 gc_args.more++;
1724 }
1725
1726 return 0;
1727 }
1728
1729 static DEFINE_SPINLOCK(fib6_gc_lock);
1730
1731 void fib6_run_gc(unsigned long expires, struct net *net, bool force)
1732 {
1733 unsigned long now;
1734
1735 if (force) {
1736 spin_lock_bh(&fib6_gc_lock);
1737 } else if (!spin_trylock_bh(&fib6_gc_lock)) {
1738 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
1739 return;
1740 }
1741 gc_args.timeout = expires ? (int)expires :
1742 net->ipv6.sysctl.ip6_rt_gc_interval;
1743
1744 gc_args.more = icmp6_dst_gc();
1745
1746 fib6_clean_all(net, fib6_age, NULL);
1747 now = jiffies;
1748 net->ipv6.ip6_rt_last_gc = now;
1749
1750 if (gc_args.more)
1751 mod_timer(&net->ipv6.ip6_fib_timer,
1752 round_jiffies(now
1753 + net->ipv6.sysctl.ip6_rt_gc_interval));
1754 else
1755 del_timer(&net->ipv6.ip6_fib_timer);
1756 spin_unlock_bh(&fib6_gc_lock);
1757 }
1758
1759 static void fib6_gc_timer_cb(unsigned long arg)
1760 {
1761 fib6_run_gc(0, (struct net *)arg, true);
1762 }
1763
1764 static int __net_init fib6_net_init(struct net *net)
1765 {
1766 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
1767
1768 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net);
1769
1770 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
1771 if (!net->ipv6.rt6_stats)
1772 goto out_timer;
1773
1774 /* Avoid false sharing : Use at least a full cache line */
1775 size = max_t(size_t, size, L1_CACHE_BYTES);
1776
1777 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL);
1778 if (!net->ipv6.fib_table_hash)
1779 goto out_rt6_stats;
1780
1781 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
1782 GFP_KERNEL);
1783 if (!net->ipv6.fib6_main_tbl)
1784 goto out_fib_table_hash;
1785
1786 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
1787 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1788 net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
1789 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1790 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
1791
1792 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1793 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
1794 GFP_KERNEL);
1795 if (!net->ipv6.fib6_local_tbl)
1796 goto out_fib6_main_tbl;
1797 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
1798 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1799 net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
1800 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1801 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);
1802 #endif
1803 fib6_tables_init(net);
1804
1805 return 0;
1806
1807 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1808 out_fib6_main_tbl:
1809 kfree(net->ipv6.fib6_main_tbl);
1810 #endif
1811 out_fib_table_hash:
1812 kfree(net->ipv6.fib_table_hash);
1813 out_rt6_stats:
1814 kfree(net->ipv6.rt6_stats);
1815 out_timer:
1816 return -ENOMEM;
1817 }
1818
1819 static void fib6_net_exit(struct net *net)
1820 {
1821 rt6_ifdown(net, NULL);
1822 del_timer_sync(&net->ipv6.ip6_fib_timer);
1823
1824 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1825 inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers);
1826 kfree(net->ipv6.fib6_local_tbl);
1827 #endif
1828 inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers);
1829 kfree(net->ipv6.fib6_main_tbl);
1830 kfree(net->ipv6.fib_table_hash);
1831 kfree(net->ipv6.rt6_stats);
1832 }
1833
1834 static struct pernet_operations fib6_net_ops = {
1835 .init = fib6_net_init,
1836 .exit = fib6_net_exit,
1837 };
1838
1839 int __init fib6_init(void)
1840 {
1841 int ret = -ENOMEM;
1842
1843 fib6_node_kmem = kmem_cache_create("fib6_nodes",
1844 sizeof(struct fib6_node),
1845 0, SLAB_HWCACHE_ALIGN,
1846 NULL);
1847 if (!fib6_node_kmem)
1848 goto out;
1849
1850 ret = register_pernet_subsys(&fib6_net_ops);
1851 if (ret)
1852 goto out_kmem_cache_create;
1853
1854 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib,
1855 NULL);
1856 if (ret)
1857 goto out_unregister_subsys;
1858
1859 __fib6_flush_trees = fib6_flush_trees;
1860 out:
1861 return ret;
1862
1863 out_unregister_subsys:
1864 unregister_pernet_subsys(&fib6_net_ops);
1865 out_kmem_cache_create:
1866 kmem_cache_destroy(fib6_node_kmem);
1867 goto out;
1868 }
1869
1870 void fib6_gc_cleanup(void)
1871 {
1872 unregister_pernet_subsys(&fib6_net_ops);
1873 kmem_cache_destroy(fib6_node_kmem);
1874 }
1875
1876 #ifdef CONFIG_PROC_FS
1877
1878 struct ipv6_route_iter {
1879 struct seq_net_private p;
1880 struct fib6_walker w;
1881 loff_t skip;
1882 struct fib6_table *tbl;
1883 int sernum;
1884 };
1885
1886 static int ipv6_route_seq_show(struct seq_file *seq, void *v)
1887 {
1888 struct rt6_info *rt = v;
1889 struct ipv6_route_iter *iter = seq->private;
1890
1891 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen);
1892
1893 #ifdef CONFIG_IPV6_SUBTREES
1894 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen);
1895 #else
1896 seq_puts(seq, "00000000000000000000000000000000 00 ");
1897 #endif
1898 if (rt->rt6i_flags & RTF_GATEWAY)
1899 seq_printf(seq, "%pi6", &rt->rt6i_gateway);
1900 else
1901 seq_puts(seq, "00000000000000000000000000000000");
1902
1903 seq_printf(seq, " %08x %08x %08x %08x %8s\n",
1904 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt),
1905 rt->dst.__use, rt->rt6i_flags,
1906 rt->dst.dev ? rt->dst.dev->name : "");
1907 iter->w.leaf = NULL;
1908 return 0;
1909 }
1910
1911 static int ipv6_route_yield(struct fib6_walker *w)
1912 {
1913 struct ipv6_route_iter *iter = w->args;
1914
1915 if (!iter->skip)
1916 return 1;
1917
1918 do {
1919 iter->w.leaf = iter->w.leaf->dst.rt6_next;
1920 iter->skip--;
1921 if (!iter->skip && iter->w.leaf)
1922 return 1;
1923 } while (iter->w.leaf);
1924
1925 return 0;
1926 }
1927
1928 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter)
1929 {
1930 memset(&iter->w, 0, sizeof(iter->w));
1931 iter->w.func = ipv6_route_yield;
1932 iter->w.root = &iter->tbl->tb6_root;
1933 iter->w.state = FWS_INIT;
1934 iter->w.node = iter->w.root;
1935 iter->w.args = iter;
1936 iter->sernum = iter->w.root->fn_sernum;
1937 INIT_LIST_HEAD(&iter->w.lh);
1938 fib6_walker_link(&iter->w);
1939 }
1940
1941 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl,
1942 struct net *net)
1943 {
1944 unsigned int h;
1945 struct hlist_node *node;
1946
1947 if (tbl) {
1948 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1;
1949 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist));
1950 } else {
1951 h = 0;
1952 node = NULL;
1953 }
1954
1955 while (!node && h < FIB6_TABLE_HASHSZ) {
1956 node = rcu_dereference_bh(
1957 hlist_first_rcu(&net->ipv6.fib_table_hash[h++]));
1958 }
1959 return hlist_entry_safe(node, struct fib6_table, tb6_hlist);
1960 }
1961
1962 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter)
1963 {
1964 if (iter->sernum != iter->w.root->fn_sernum) {
1965 iter->sernum = iter->w.root->fn_sernum;
1966 iter->w.state = FWS_INIT;
1967 iter->w.node = iter->w.root;
1968 WARN_ON(iter->w.skip);
1969 iter->w.skip = iter->w.count;
1970 }
1971 }
1972
1973 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1974 {
1975 int r;
1976 struct rt6_info *n;
1977 struct net *net = seq_file_net(seq);
1978 struct ipv6_route_iter *iter = seq->private;
1979
1980 if (!v)
1981 goto iter_table;
1982
1983 n = ((struct rt6_info *)v)->dst.rt6_next;
1984 if (n) {
1985 ++*pos;
1986 return n;
1987 }
1988
1989 iter_table:
1990 ipv6_route_check_sernum(iter);
1991 read_lock(&iter->tbl->tb6_lock);
1992 r = fib6_walk_continue(&iter->w);
1993 read_unlock(&iter->tbl->tb6_lock);
1994 if (r > 0) {
1995 if (v)
1996 ++*pos;
1997 return iter->w.leaf;
1998 } else if (r < 0) {
1999 fib6_walker_unlink(&iter->w);
2000 return NULL;
2001 }
2002 fib6_walker_unlink(&iter->w);
2003
2004 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net);
2005 if (!iter->tbl)
2006 return NULL;
2007
2008 ipv6_route_seq_setup_walk(iter);
2009 goto iter_table;
2010 }
2011
2012 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos)
2013 __acquires(RCU_BH)
2014 {
2015 struct net *net = seq_file_net(seq);
2016 struct ipv6_route_iter *iter = seq->private;
2017
2018 rcu_read_lock_bh();
2019 iter->tbl = ipv6_route_seq_next_table(NULL, net);
2020 iter->skip = *pos;
2021
2022 if (iter->tbl) {
2023 ipv6_route_seq_setup_walk(iter);
2024 return ipv6_route_seq_next(seq, NULL, pos);
2025 } else {
2026 return NULL;
2027 }
2028 }
2029
2030 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter)
2031 {
2032 struct fib6_walker *w = &iter->w;
2033 return w->node && !(w->state == FWS_U && w->node == w->root);
2034 }
2035
2036 static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
2037 __releases(RCU_BH)
2038 {
2039 struct ipv6_route_iter *iter = seq->private;
2040
2041 if (ipv6_route_iter_active(iter))
2042 fib6_walker_unlink(&iter->w);
2043
2044 rcu_read_unlock_bh();
2045 }
2046
2047 static const struct seq_operations ipv6_route_seq_ops = {
2048 .start = ipv6_route_seq_start,
2049 .next = ipv6_route_seq_next,
2050 .stop = ipv6_route_seq_stop,
2051 .show = ipv6_route_seq_show
2052 };
2053
2054 int ipv6_route_open(struct inode *inode, struct file *file)
2055 {
2056 return seq_open_net(inode, file, &ipv6_route_seq_ops,
2057 sizeof(struct ipv6_route_iter));
2058 }
2059
2060 #endif /* CONFIG_PROC_FS */
Linux with added FPC-III support